An Observational Retrospective Demographic Study of Patients with Oral Squamous Cell Carcinoma Treated with Radiation Therapy at Charlotte Maxeke Johannesburg Academic Hospital (2014-2019)

Abstract

Background and objectives Squamous cell carcinoma (SCC) of the oral cavity comprises defined anatomical subsites and is related to known risk factors such as alcohol consumption and tobacco smoking. It is more prevalent in men than in women and commonly develops in middle- to older age. Unfortunately, it is often diagnosed late during its natural course when the disease is already at an advanced clinical stage, and consequently, patients with the disease have a low 5-year survival rate. Definitive radiation therapy and concurrent chemoradiation therapy are the primary options of treatment for patients with unresectable oral SCC or for those who cannot, or do not want to undergo surgery. Radiation therapy is also an important adjuvant treatment following primary surgery in select cases, and has a role in the salvage and palliative settings. The aim of this study was to describe the relationship between the demographic characteristics of patients who presented to the Department of Radiation Oncology at Charlotte Maxeke Johannesburg Academic Hospital, and the clinical and pathological features of the disease, and to describe the treatment-induced toxicities that occurred. Materials and methods In this cross-sectional, retrospective study, clinic records were reviewed of all patients with oral cavity SCC treated with radiotherapy in the Department of Radiation Oncology at Charlotte Maxeke Johannesburg Academic Hospital, between January 1st 2014 and December 31st 2019. Only patients with histologically confirmed oral cavity SCC were included; other anatomical subsites (such as oropharyngeal carcinoma, among others), and other oral cavity malignancies (such as adenocarcinoma or lymphoma, among others) were excluded. Age, sex, race/ethnicity, smoking and alcohol consumption, clinical stage, histopathological grade, oral cavity subsite, treatment intent and radiation-induced toxicities were recorded, tabulated, and statistically analyzed. v Results Of the 119 cases of oral SCC included in this study, 71% were males (mean age: 59 years) and 29% were females (mean age: 62 years). The mean age of the study population at the time of radiotherapy was 60 years. The percentage of males that smoked (94%) was significantly higher than that of females (66%), and the percentage of males that consumed alcohol (73%) was significantly higher than the percentage of females who consumed alcohol (49%). The tongue was the most frequent subsite affected followed by the floor of the mouth. The tongue and floor of the mouth accounted for 71% of all cases. Both the tongue and floor of the mouth were associated with advanced clinical stage (stage III and IV) and most of the oral SCC at the different subsites were moderately-differentiated. In this study, 72/119 patients (61%) experienced oral mucositis, in line with the prevalence reported in the literature, with males affected to a statistically significantly greater degree than females. Salivary gland dysfunction was noted in 13% of patients and most frequently affected patients who received definitive chemoradiotherapy. Radiation-induced dermatitis was present in 62% of patients (74/119) and was also most frequently observed in patients who had received definitive chemoradiotherapy. Conclusion The results of this study confirm that oral SCC is predominantly a disease of middle- aged or elderly people, is more frequently observed in males than in females, and may affect any oral subsite, although the tongue and floor of mouth were noted to be the most common in our study. Our results are also in line with previous findings that show that men with oral cavity SCC smoked and consumed alcohol to a greater degree than did women, and that this may be the reason for the observed gender disparity seen in the literature. All patients in this study were affected by one or more radiation-induced toxicities. Dermatitis, oral mucositis and dysphagia were the most frequently observed adverse side-effects, and some of the patients experienced more than one radiation-induced toxicity. All toxicities were managed as per Departmental protocols.